Sound-producing apparatus



July 23, 1929. G. s. HARRIS SOUND PRODUC ING APPARATUS Filed May 18, 1927 fig.

Inventor: Geor-oe S. Harm neg.

Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

GEORGE S. HARRIS, OF SCHENECTADY, NEW YORK, ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SOUND-PRODUCING APPARATUS.

Application filed May 18,

My invention relates to sound producing apparatus comprising a diaphragm of. sheet metal or the like, and has for its princiaal object the provision of an improved arrangement whereby such a diaphragm may be readily mounted and subjected to a uniform tensile force of any desired value.

In order to avoid distortion of the sound transmitted through a diaphragm, it is desirable that the diaphragm be subjected to a stretching force which is uniform in all directions. The various means heretofore provided for this purpose have not been altogether satisfactory because they fail to produce a positive and uniform grip on the edge of the diaphragm which is frequently injured due to scraping, distortion or cutting. In accordance with my invention, these difliculties are largely avoided by the provision of wedgeshaped stretching rings arranged to positively grip and uniformly stretch the material of which the'diaphragm is made.

'My invention will be better understood from the following description when considered in connection with the acompanying drawingsand its scope will be pointed out in the appended claims.

Referring to the drawings, Figs. 1 to illustrate diflerent views of a sound producing apparatus constructed in accordance with ,my invention.

This apparatus comprises clamping members l and 2 which are connected together by i screws 3 and are provided at their opposed faces with wedge-shaped grooves 4 and 5.

These grooves are adapted to receive the beveled edges of a pair of stretching rings 6 and 7 made of brass or the like and arranged to grip the edge of a diaphragm 8. In order to ensure that the diaphragm 8 is positively gripped between the opposed edges of the two stretching rings, the ring 7 may be provided with a groove 9 arranged to register with an extension 10 on the ring 6.

\Vith this arrangement, the diaphragm 8 is positively gripped between the stretching rings 6 and 7 and it may be subjected to any 1927. \SeriaI No. 192,469.

desired tension by tightening the screws 3 and expanding the rings 6 and 7, but it will not be'distorted nor cut due to the fact that the rings are expanded in a manner to uniformly stretch all parts of the diaphragm. This uniformity in the pressure applied to the edges of the diaphragm not only prevents sound distortion but also permits the use of sheet disks made of duraluminum (an alloy of aluminum, magnesium and copper) and other readily obtainable materials which have heretofore been considered unfit for use in the con struction of diaphragms.

IVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination of a diaphragm, beveled stretching rings arranged to engage the opposite sides of the edge of said diaphragm, and means for causing said diaphragm to be gripped and stretched by said rings.

2. The combination of a diaphragm, beveled stretching rings arranged to engage the opposite sides of the edge of said diaphragm, and a pair of clamping members arranged to be forced toward one another for causing said diaphragm to be gripped andstretched by said 11in s.

3. The method of mounting a sound producing diaphragm which comprises placing the edge of said diaphragm between a pair of beveled rings, applying a force to said rings to grip said edge, and increasing said force-to expand said rings and stretch said diaphragm. Y

4. The combination of a diaphragm, beveled stretching rings arranged to engage the opposite sides of the edge of said diaphragm,

a pair of clamping members provided with beveled grooves each adapted to receive an edge of one of said rings, and means arranged to force the edges of said rings into said grooves for gripping the edge of said diaphragm and stretching said rings.

In witness whereof, I have hereto set my hand this 17th day of'May, 1927.

GEORGE s. HARRIS. 

